The present invention relates to agents for lightening keratinic fibers, particularly human hair, wherein the agents contain, in addition to a chemical oxidizing agent, at least one specific sulfonimine. Use of such an agent on keratinic fibers significantly improves the lightening performance of lightening and hair-bleaching agents. The present invention further relates to a multi-component packaging unit (kit of parts) for lightening keratinic fibers that comprises, packaged separately from one another, at least one agent containing a specific sulfonimine, an oxidizing agent preparation, and optionally a hair-bleaching powder.
Lightening of one's hair color has long been a desire of many consumers, since a blond hair color is regarded as attractive and as desirable in terms of fashion. A variety of hair-bleaching agents having different levels of hair-bleaching performance are commercially available for this purpose. The oxidizing agents present in these products are capable of lightening hair fibers by oxidizative destruction of the hair's own melanin dye. For a moderate hair-bleaching effect, it is sufficient to use hydrogen peroxide (optionally with the addition of ammonia or other alkalizing agents) as the only oxidizing agent. In order to achieve a more pronounced hair-bleaching effect, a mixture of hydrogen peroxide and peroxodisulfate salts and/or peroxomonosulfate salts is typically used.
Lightening is, unfortunately, also accompanied by damage to the hair, since not only the hair's dyes but also other structural constituents of the hair are damaged by oxidation. The extent of damage can range from hair that is coarse, brittle, and more difficult to comb out, to decreased hair strength and tear resistance, to actual hair breakage. The greater the amount of hydrogen peroxide and optional peroxodisulfate used, the greater the damage generally caused to the keratin fibers. Hair coloring or lightening agents having good lightening performance without at the same time damaging the hair fibers are not known to date.
The present invention report therefore provides novel agents for lightening or bleaching of hair that are comparable or superior in terms of their lightening performance to those agents typically available on the market, while at the same time having decreased hair damage. For consumers with very dark hair, it is not possible to generate light-colored blond shades even when using high concentrations of hydrogen peroxide in combination with persulfate salts. Repeated applications are also not possible because of increasing hair damage. The present invention therefore also makes available an agent whose lightening capability exceeds that of the currently marketed agents made up of hydrogen peroxide and peroxodisulfate salts (sodium peroxodisulfate, ammonium peroxodisulfate, and/or potassium peroxodisulfate).
A large number of organic compounds are mentioned in the literature as effective agents for activation of peroxo compounds. U.S. Pat. No. 5,047,163 and U.S. Pat. No. 5,041,232 disclose specific sulfonimines that, in the presence of peroxo compounds, particularly inorganic peroxo compounds such as peroxomonosulfates, and further adjuvants, produce improvements in bleaching behavior in textile bleaching. Use of the corresponding sulfonimines in hair-bleaching agents for the lightening of hair is not hitherto known. Use of the sulfonimine derivatives according to the present invention for the activation of peroxo compounds is therefore known from the literature. It is not known from the existing art, however, that the lightening effect on hair can also be intensified by the use of sulfonimines in cosmetic hair-bleaching agents.
Different application parameters, which in some cases differ sharply from one another, are chosen for textiles bleaching and hair lightening, so that experimental results from one application sector are not transferable to the other. For example, both the formulation and temperatures selected for the two bleaching processes are very different. It was therefore not foreseeable that the activation, demonstrated in the washing-agent sector, of peroxo compounds by the sulfonimine derivatives according to the present invention might result in an intensifying of the hair-bleaching effect in the bleaching of hair as well.